CHOPP3R is a search-and-rescue helicopter made from a single 31313 Lego Mindstorms EV3 set. I built this as a potential model for a book, but as the book has not materialised I decided to publish it instead! CHOPP3R has working top and rear rotors driven my a medium motor. It searches for a liferaft containing the beacon using the IR sensor mounted under the cockpit. There is a winch mounted on the side to lower a rescue rope that is controlled using the up/down buttons on the EV3. I’m particularly pleased with this model as it looks realistic and yet only uses a single 31313 EV3 set to build. It just shows you that a single set can give you a lot of flexibility.
The Chopp3r.ev3 control program for CHOPP3R is broken into four parts.
- Monitor the touch sensor. If it is pressed then toggle the boolean variable flying
- If flying is true then turn on the rotor motor, otherwise turn it off.
- If flying is true then get the distance reading from the IR sensor and use that to compute the delay between beeps.
- Monitor the up/down buttons and power the winch motor.
To use this model all you need to do is:
- Press the top button on the IR beacon to put it into beacon mode; the green LED in the IR beacon should illuminate.
- Download and run the program on the EV3.
- Press the touch sensor to start the rotors.
- As the chopper gets closer to the IR beacon the beeps will get progressively quicker.
I made building instructions for this model available as a RescueChopper.pdf. Be warned; it’s a 21MB file so best to right-click and Save As… before viewing.
ERRATA: There is a mistake in the building instruction PDF at step 25. Two parts are missing to hold the EV3 onto the Chopper body. You need to attach a Technic Beam 3 x 3.8 x 7 Liftarm Bent 45 Double (part 32009) to both sides of the EV3. See the pictures in the gallery below for details.
CABLES: Connect the cables as follows:
- Motor A: small motor driving the rotors
- Motor D: winch motor
- Port 1: Ultrasonic sensor
- Port 4: Touch sensor
Jul 22, 2014 @ 12:28:16
Great if fly
Aug 20, 2014 @ 07:54:49
Hi there,
Just wondering does it actually fly
From Tim
Aug 31, 2014 @ 21:00:33
Unfortunately no Tim – it would need a much stronger motor and real rotor blade 🙂
Aug 23, 2014 @ 13:25:49
but wich chanel do I use
Aug 31, 2014 @ 18:23:04
This is a great model! Too bad the building instructions are incomplete or don’t match the pics above:
– EV3 brick hanging because it’s not attached at the back as we can see on your last pic
– tail rotor can’t rotate because it’s not connected its axle
Could you update the building instructions?
Aug 31, 2014 @ 21:12:35
Julien – thanks for the feedback and also spotting that error. I’ll add the missing support beams so that the EV3 doesn’t hang down. On the tail rotor: there is a rubber band driving the tail rotor from the axle. You can see it in the pictures if you look closely, but I could not figure out how to add rubber bands in Ldraw. There is one red rubber band in the EV3 set – you can use that.
Sep 27, 2014 @ 19:00:07
The link to the building instructions is broken 🙁
Nov 01, 2014 @ 14:10:06
Sorry – I uploaded a new file now
Oct 18, 2014 @ 14:12:29
The link to the instructions is not working. Can you repost the link or something??
Nov 01, 2014 @ 14:09:47
Yes, it’s uploaded now. Sorry!
Oct 30, 2014 @ 09:01:34
hello, im so exicited with your model. but when I try to download, it says the file already deleted.
could you upload it again or can you send me the instruction via email. I will be glad if you will. Thx before and sorry for my bad english.
Nov 01, 2014 @ 14:09:29
Hi – sorry the file got moved so I uploaded it again. It should work now!
Nov 02, 2014 @ 09:50:11
The Link to the Chopp3r.ev3.zip is not available. Can you please upload again?
thx
Markus
Nov 02, 2014 @ 09:52:17
The Link to the control program is not available. Can you please upload again?
thx
Markus
Nov 02, 2014 @ 13:12:17
Sorry, the link was borked. I re-uploaded it now
Nov 02, 2014 @ 21:12:03
Thanks
Dec 31, 2014 @ 06:09:34
I don’t see the link to get the helicopter build instructions… Can you type the address down? Thank you!
Jan 01, 2015 @ 16:30:46
Did you see the link to RescueChopper.pdf on the page?
Jan 23, 2015 @ 13:59:03
Hi, the building instructions appear to use more than 10 of 4142135, and the retail set has only 10. Could you please take a look at that? Thanks.
Feb 14, 2016 @ 23:22:01
also in the building instructions there are 5 beams 4562805 (the red ones) and the retail set has only 4 of them
Mar 29, 2016 @ 10:08:26
My 11 years old nephew has just built it. I dowloaded the program for him. Thank you for sharing this great project.! We only have problem with ultrasonic sensor – this function: “4. As the chopper gets closer to the IR beacon the beeps will get progressively quicker” seems to not working (or I have done something wrong). Could you please confirm that the “Search” project contains the program for this function? Thnak you very much!
May 03, 2016 @ 12:55:11
I have a student who has this chopper built and is wanting to use it in our school’s science fair he has it partially programmed using a program he has designed, but he sees on your sight here that your have a link to a program. It will not let us download it for some reason is there something we need to download it? Or can you email it to us? Thanks so much my email is acorley@hamlin.esc14.net science teacher in middle of no where Texas!!!
May 03, 2016 @ 21:46:00
Sent you a reply via email!
Jun 14, 2016 @ 12:57:31
The model seems to use more than the four red 11 hole technic beams in the 31313 kit. It uses five. Could you fix that?
Aug 23, 2016 @ 22:24:30
Sorry that’s right – a few people have pointed it out to me but I’ve never had a chance to rebuild it.